Ben Fry tends to be the most mentioned name when people (at least from my 'generation') are asked how we got initially interested in data visualization. Those who wonder why, might want to read his Ph.D. thesis, while keeping in mind that it was written back in 2004 (and so most of the work was accomplished several years before). Others might know Ben from his book Visualizing Data, or of his past works, including Isometric Blocks, All Streets and The Origin of Species, which are all still exemplary for those concerned with combining function with beauty, in the context of data visualization.
Put differently, one should definitely be interested in the short, 8-minute interview with Mac Slocum, managing editor of O'Reilly Media. The conversation focused on the current popularization of visualization ("If we put these [visualization] tools in the wrong people hands, is there a danger to spread misinformation?"), and how visualization will evolve in the future.
An interesting bit includes his assertion that visualization should not be interpreted as a "monolothic thing", but instead should be considered similar to writing. Consequently, some tools are meant for complex data analysis while others focus more on entertainment, and both should not be evaluated out of context.
On this topic, read also a recent interview with Moritz Stefaner over at visualizing.org.